Grinding machine



Aug. 23, 1932. w. F. FRASER GRINDING MACHINE Filed July 25. 1927 3Sheets-Sheet l allzl" IIIIIIIIIIIIIIIIIIIII I IIIIIIIIIIIIIIIIIIIIIIIllIf/lV/ll a l:

'INVENTOR.

ATTORNEY.

Aug. 23, 1932. w. .F. FRASER GRINDING MACHINE Filed July 25, 1927 Fig.3.0

3 Sheets-Sheet 2 Aug. 23, 1932. w E ER 1,873,751

- GRINDING MACHINE Filed July 25. 1927 s She ets-Sheet 5 Fig.4.

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Patented Aug. 23, 1932 stares PATENT ersice .WAEEEN F. FRASER, FWESTBOBQ, MASSACHUSETTS I GRINDING MACHINE V Application filed July 25,1927. Serial No. 208,185.

' This invention relates to grinding ma- Themachine shown comprises agrinding chines and is especially concerned with grindwheel 2 and a worksupport 8 which isshown ing machines of the automatic type. somewhatdiagrammatically in Fig. 4. This I It is the general object of theinvention to machine is of the so-called cylindrical type 'fiimprovemachines of this character with a and it is designed especially forgrinding 55 view to producing more accurate and nut work havingcylindrical or tapered external form results, and facilitating themaking of surfaces such as pistons, shafts, shackle bolts, exact andrapid adjustments. g and the like. A work support of any suitable Theinvention will be herein disclosed as construction may be used in it,the support embodied in a machine of the type in which shown at 3 beingdesigned to revolve an arti- 60 the wheel head and the work support arecle of work W around a stationary axis while mounted to produce relativeapproaching the grinding wheel 2 operates on it, suitable and recedingmovements of the work and mechanism being provided, if desired, toprogrinding wheel, In such machines the apduce a relativetraversingmotion of the preaching movement must be controlled very Wheeland work. 65

exactly in order to produce accurate results. The work support ismounted on upright T have found thatin machines of this, type extensionsof the machine frame or base 4, the presence of oil films between theparts while the wheel 2 is mounted in a wheel head which limit theapproaching movement is deor wheel support 5 which can be movedtocidedly detrimental to the high degree of acward or from the work. Forthis purpose 7O "curacy required in many classes of work. the support 5is mounted on a bed 6which is Accordingly, it is an important object ofthis provided with a V-shaped guideway 7 and a invention to devise aconstruction in'which flat guideway 8, ,(see Figs. 3 and 5) the sup- 7errors arising from this cause will be .elimport 5 havingcorrespondingly shaped parts inated. to fit these guideways- Thisconstruction 75 The'nature of the invention will be readily permits asliding movement of the whole und rstood from the following descriptionwheel head or wheel support 5 toward or when read in connection withtheaccompanyfrom the work W. V ing drawings, and the novel features willbe The approaching movement of the wheel .30 particularly pointed out inthe appended toward the work is produced by a spring 10, S0

' claims. Fig. 3, which is held in a casing 12 and which In thedrawings, serves to force a plunger 13 outwardly,this Figure 1 is a planview showing those plunger carrying a threaded stud or bolt 1 v parts ofa grinding machine with which the which is adjustable in the plunger 13.The present invention is more especially constud or bolt 1 L acts on oneend of a lever'15, 85 cerned the opposite end of this lever bearingagainst Fig. 2 is a perspective View showing a dea bar 16, Fig. 4,whichis rigidly mounted in tail of construction; j the wheel support 5but is adjustable rela- Fig. '3 is a plan view of a portion of thetively thereto; So far as the operatlon of the machine frame andbed, thewheel headbeing spring 10 on the wheel support is concerned, 90

removed; 1 I the bar 16 may be considered to be an inte- Fig. 4isavertical, cross-sectional view ap gral part of the support 5. It Wlllbe ev1- proximately on the line le-4, Fig.1; 1 dent from an inspectionof Figs. 3 and 4 that T Fig. 5 is a cross-sectional view through the thespring 10 tends constantly to force the wheel head and a part of thesupporting bed wheel 2 toward the work W. a r '95 therefor, the sectionbeing taken approxi The receding movement of the wheel relamately onthe. line 5-5,. Fig. 1; and tively to the work is produced by a powerFig. 6 is a front View, partly in vertical driven mechanism whichcomprises a cam 17, cross-section, showing certain details of the Fig.4, secured fastona driven shaft 1 8 and wheel head adjusting mechanism.arranged toosclllate a lever 20 which 1s fulcrumed on the machine frameat 21. An inclined guideway is provided on the upper side of this leverin which a wedge 22 is mounted, this wedge having a rod 23 connected toit which extends through an upright projection 24 on the rearward end ofthe lever. Nuts 2525, Fig. 4, threaded on the righthand end portion ofthe rod 23 serve to adjust this rod longitudinally, and this adjustment,in turn, adjusts the wedge 22 in its guideway. Bearing on the wedge 22is an upright pin or rod 26, and one arm 27 of a bell crank lever bearson the upper end of t iis pin, while its other arm 28 engages a verticalface 30 formed on the bar 16. 2728 is supported on a pivot 31 which ismounted in cars 32-32, 2, of a bracket 33 which is set into a socketformed in the machine bed 6, the bracket being bolted securely to thebed so that it is to all intents and purposes, so far as-operation isconcerned, an integral part of the bed.

It will be observed that when the machine is in operation the spring 10will tend to hold the wheel 2 in contact with the work l/V, but thatwhen the high part of the cam 17 operates to raise the lever 20,this'movement will be transmitted through the pin 26 and bell cranklever 2728 to the bar 16 which, being rigid with the wheel support 5,will give the wheel a receding or withdrawing movement away from thework. In a completely automatic machine the work is changed during thisreceding movement and a new article of work is presented to the wheelbefore the cam 17 again permits the lowering of the lever 20 and allowsthe spring 10 to move the wheel 2 again into contact with the work. Theshape of this cam is such that after the wheel has engaged the work thecam still controls the rate of approach or feed of the wheel.

As above indicated, an important feature of this invention resides inthe mechanism which limits the work approaching movement of the wheel 2.Referring to Figs. 2, 3 and 4 it will be seen that a bar 34 is securedin the recess 35 in the bracket 33, and that when the lowering movementof the lever 20 occurs, the work approaching movement of the wheel willbe limited by the engagement of portions of the upright face 30 on thebar 16 with faces 39 of this fixed bar 34; In other words, this bar 34acts as a stop, since it is 'xounted in a fixed position with referenceto the machine frame. The time at which the approaching movement of thewheel head or work support 5'is stopped in the rotation of the cam 17may be varied by adjusting the wedge 22 in the manner above described.That is, the bar 16 will strike the stop 34 and thus limit'theapproaching movement of the wheel head at some time during the strokewhich is imparted to the lever 20 by the cam 17, and the point in thisstroke at which such The bell crank lever stopping of the movement ofthe wheel head occurs may be determined by adjusting the wedge 22. Theportion of the stroke of said lever 20 which occurs after the wheel headis stopped results simply in a dwell or pause in the movement of thewheel head. It will be noted that the right-hand face, Fig. 4,.of thelever arm 28 moves into and out of contact with the upright face 30 onthe bar 16, and that the upright face 30 also moves into and out ofcontact with the faces 39 on the bar 34. The pivot or fulcrum 31 for thelever 27-28 is positioned in a pocket formed in the base 6 which isadapted to hold a quantity of oil so that the pivot may be welllubricated, but the cooperating faces of the stop 34 and bar 16 are alllocated a substantial distance above this pocket so that they are keptsubstantially free of oil. They are also protect ed from dustby the factthat they are located under the wheel head 5 in a substantially closedchamber. This arrangement thus eliminates inaccuracies in the work whichotherwise would be caused by the presence of oil or dust films on thesurfaces of the parts which limit the work approaching movement.

In order to adjust the wheel angularly with reference to the work, thebed 6 on which the wheel support 5 slides is mounted on a horizontalplaned surface on the frame or base 4 and is pivoted on a bushing 36through which the pin 26 projects. An extension 37 of this bed projectsforward through the front of the frame 4 and overlies a bracket 38 rigidwith the frame. Adjusting screws 40-40 are threaded through upright lugsformed on this bracket and bear against the opposite sides of theextension 37 where they can be conveniently manipulated to adjust theangular relationship of the grinding wheel and the work. A bolt 41projects through both the extension 37 and the bracket 38 and serves tolock the bed in its adjusted position.

For the purpose of adjusting the grinding Wheel to work of differentdiameters, the bar 16 is mounted to slide in the wheel support 5 but isprevented from rotating by the key 42, Fig. 4, and the forward orleft-hand end of the bar is screw threaded, as shown at 43. Aninternally threaded sleeve 44 is mounted on the threaded portion 43 ofthe bar and is secured by means of a key and a nut 47 to a hand wheel 45through which the sleeve maybe rotated to adjust the bar 16, andconsequently the wheel 2, toward or from the work. The sleeve is held byparts 46 and 47-against axial movement relatively to the bracket 56which is secured to the support 5 by means of the part 59. This permitsa fine adjustment of the bar 16 with relation to the wheel head, and theperiphery of the hand wheel 45 preferably is graduated, as shown in Fig.l, to cooperate with a stationary pointer 48, Figs. 1 and 4, in makingthese adjustments.

For extremely fine adjustments a micrometer screw mechanism also isprovided. That is, a worm wheel 50 is bolted securely to the hand wheel45 which is keyed to the sleeve 46 so that it must rotate with it, and amicrometer screw 51, Fig. 6, is arranged to mesh with and drive the wormwheel 50. This screw is mounted on the lower end of a shaft 52 which isrotatably supported in a bracket 53, the upper end of the shaft beingprovided with a graduated finger wheel 54. The bracket 53 is pivoted at55, Fig. 6, on a stationary casing 56 in which the screw threaded sleeve44 is mounted, and this pivotal support permits the movement of themicrometer screw into or out of mesh with the worm wheel 50. Normallythe screw is held out of contact with the worm wheel by a spring 57,Figs. 1 and 6, which encircles a rod 58 and bears against a portion ofthe bracket 53. It may be moved into mesh with the worm wheel, however,by a cam 6O having a handle 61, the cam being mounted to rotate on therod 58 and cooperating with a stationary cam member 62, secured on. saidrod, to force the lower end of the bracket inwardly far enough to carrythe screw 51 into mesh with the worm wheel 50 and hold it there. A pin63, Fig. 6, projecting from the cam 60 and, working in a slot formed inthe bracket 53, limits the operative move ment of the cam. Fig. 6 showsthe micrometer adjusting mechanism in its operative position. When thehandle 61 is moved backwardly the spring 57 immediately throws the screw51' out of mesh with the worm wheel 50.

The screw threaded mechanism which cooperates with the left-hand end,Fig. 4, of the bar 16 serves to make adjustments of the wheel head orwheel support 5 relatively to the bar 16, the bar being held between thelevers 15 and 28, so that the grinding wheel is adjusted relatively tothe work, and these adjustments can be made very minute, if desired,through the use of the micrometer mechanism. These adjustments alsodetermine the relationship of the grinding wheel to the work.

The invention thus provides a grinding machine in which extreme accuracycan be obtained and in which this accuracy is not likely to be disturbedby-the presence of oil films, dust or the like.

While a preferred embodiment of the invention has been herein shown anddescribed, it will be understood that the invention may be embodied inother forms without departing from the spirit or scope thereof.

Having thus described my invention, what I desire to claim as new is:

I claim:

1. In an automatic grinding machine, the combination of a wheel support,a work support, a machine bed having guideways upon .1 which one of saidsupports is mounted for sliding movement to produce a relativeapproaching or" receding movement of the Work and grinding wheel, a baradjustable in said slidable support, screw threaded means for makingfine adjustments of said bar relatively to said slidable support, powerdriven mechanism operable through said bar to produce said? recedingmovement; a spring for producing said approaching movement, saidmechanism including a power, driven cam and a lever mechanism throughwhlch motion 1s transmitted from sa1d cam to said bar,

7 one of the levers of said mechanism including an arm arranged to acton the bar mone direction; and a stop for engaging said bar and limitingits movement in; the opposite direction.

2. In an automatic grinding machine, the

combination of-a grinding wheel support, a

work support, a, machine bed having guideways, upon which one, of saidsupports is mounted for sliding movement to permit relative approachingand receding movements of the work and grinding wheel, a machine framesupporting said bed, a hollow pivot connecting said bed and frame forangular adjustment of the bed on the frame, abar adjustable in saidslidable support, power driven mechanism operable through said bar toproduce said receding movement, and yieldable means for producing saidap preaching movement, said mechanism comprising a cam and connectionsbetween said cam-and said bar, lncludlng a member sl dably mounted insaid hollow pivot, for moving's'a'id bar in one direction.

3. In an automatic grinding machine, the comb nation of a grinding wheelsupport, a work support, a machine bed having guldeways upon which oneof said supports is mounted for horizontal sliding movement to producerelative approaching and receding movements of the work and grindingwheel,

a horizontal bar adjustable in said slidable support, screw threadedmeans for adjusting said bar relatively to said slidable support, saidbar having an upright shoulder, a bell crank lever mounted on said bedand having an arm to engage said shoulder and a second arm extending atan angle thereto, a power driven cam, a lever arranged to be actuated bysaid cam, and connections between the latter lever and the second arm ofsaid bell crank lever for operating said bell crank lever to cause it toengage said bar and thereby produce said receding movement of saidslidable support.

4. In an automatic grinding machine, the

combination of a grinding wheel support, a

work support, a machine bed having guideways upon which one of saidsupports is mounted for horizontal sliding movement to produce relativeapproaching and receding movements of the Work and grinding Wheel,

a horizontal bar adjustable in said slidable support, screw threadedmeans for adjusting said bar relatively to said slidable support,

said bar having an upright shoulder a bell crank lever mounted on saidbed and having an arm to engage said shoulder and a second arm extendingat an angle thereto, a power driven cam, a lever arranged to be actuatedby said cam, connections between the latter lever and the second arm ofsaid bell crank lever for operating said bell crank lever to cause it toengage said bar and thereby produce said receding movement of saidslidable support a spring for producing said relative approachingmovement, and a stop rigid With the machine frame and arrangedto engagesaid bar to limit said relative approaching movement.

5. In an automatic grinding machine, the combination of a grinding Wheelsupport; a Work support; a machine bed having guide- Ways upon Which oneof said supports is mounted for sliding movement to produce relativeapproaching and receding movements of the Work and grinding Wheel; arodadjustable in said slidable support; screw threaded means for adjustingsaid rod relatively to said support; power driven mechanism operablethrough said rod to control said approaching movement; and a stop rigidWiththe machine frame for engaging said rod and limiting saidapproaching movement, said mechanism comprising a power driven cam, alever operated thereby, means for transmitting the motion of said leverto said rod, and means adjustable to vary the range of movement impartedto sald slldable support by said cam.

WARREN F. FRASER.

